软岩矿区顶板弱含水层高强度携沙突水机理研究

Study on Mechanism of High-strength Water-inrush with Sand Caused by Weak Aquifer in Soft Rock Mining Area

近年来西北侏罗纪煤田由弱含水层引起的顶板高强度携沙突水案例多发,为查明弱含水层出大水的机制和沙源,以便于制定防治措施,从分析软岩特点入手,提出了采后覆岩移动力学结构模型"新四带"观点及实践依据,指出了形成离层水害的4个条件,明确了离层汇水作用强化了弱含水层的突水强度、泥沙自封堵作用决定了间歇式突水模式。通过案例分析,证明了上述观点的正确性,为此类事故防治提供了理论根据。

In recent years, there are many cases of high strength water inrush with sand from coal seam roof caused by weak aquifer in Jurassic coalfield in northwest China. In order to identify the mechanism of high-strength water-inrush caused by weak aquifers and sources of sand, to facilitate the development of prevention measures, this paper starts with the analysis of soft rock characteristics, and the viewpoint about the "new four-quadrant"model of the mechanical structure of overburden rock after mining and practical basis are proposed. Four conditions for formation of separated strata water damage are pointed out. It is made clear that the inrush strength of the weak aquifer is strengthened by the catchment action of separated strata, and the self-plugging effect of sediment determines the intermittent water inrush mode. It proves the correctness of the above viewpoints and provides the theoretical basis for the prevention and treatment of such accidents.